"There are equal opportunities for girls to participate in our school district and it is something that is really important to us," Irvine's assistant superintendent Cassie Parham, a former athlete, told the Associated Press. "The opportunity to be an athlete certainly exists."

Still, a spokeswoman for the NWLC said that the data used in the organization's survey, which looked at participation numbers between 2000 and 2006, painted a clear picture of widening participation gaps, which the NWLC insists is an accurate indication of inequitable opportunities between the sexes.

"On the face of it, it looks pretty difficult to say, 'Our students are unique. They're not really interested in playing the sports that other students are playing all around the state,'" NWLC Co-President Marcia Greenberger said on a conference call.

"We have an exceptional record in girls athletics," Wake County athletic director Bobby Guthrie told the News & Observer. "As a system we have done everything we can to provide equal opportunities for girls. I think we are doing that.

"I have not heard any complaints that we are not providing the proper opportunities for our girls. There haven't been any requests to add more girls sports."

Title IX, which was passed in 1979, requires schools to be compliant in three major areas or risk being illegally out of code. The code specifically requires the following three tenets to be met:

• Are female and male opportunities substantially proportionate to their respective enrollments?

• If one sex has been underrepresented, can the institution show a history and continuing practice of program expansion?

• Can the institution demonstrate that the interests and abilities of the members of that sex have been fully and effectively accommodated by the present program?

Essentially, the NWLC is cited violations of the first tenet, attempting to highlight districts with higher female enrollment but lower athletic participation rates among those populations.

The largest gap between the percentage in student body population and female participation came in Chicago, where there were 33 percent fewer female athletes than female students.

"We feel we've met all their interests, and we've provided equal access to every sport," Sandi Hicks, a representative for the Deer Valley Unified School District in north Phoenix told the Associated Press.

"All you can do is hang up your posters and make your announcements inviting girls to come out for sports," Bellaire (Texas) High girls basketball coach Mike Kramer, who is part of the Houston school district, told the Houston Chronicle. "In this district, the girls have every opportunity the boys do. It is up to those girls to come play sports."